The discretization errors of finite element approximations are examined in an abstract frame which is totally indepedent of the way of obtention of the solution. It is found that the error may be ... [more ▼]

The discretization errors of finite element approximations are examined in an abstract frame which is totally indepedent of the way of obtention of the solution. It is found that the error may be decomposed in an equilibrium error and a compatibility error, which may be combined as orthogonal vectors. Both errors admit upper and lower bounds which may be computed in a post-treatment scheme. [less ▲]

Tailor's results on machining optimization always assume that the power of the machine tool is not a limitation. However, this not necessarily true, specially in the case of rough machining, where ... [more ▼]

Tailor's results on machining optimization always assume that the power of the machine tool is not a limitation. However, this not necessarily true, specially in the case of rough machining, where Taylorian optima are out of the power range of the machine. In this paper, an algorithm is proposed, where the machine capacity is the first consideration. The obtained result is then corrected in view of the tool life. [less ▲]

This report focuses on the classical Taylorian optimization of the cuting speed. An interesting result is the supply curve of the turning operation, which has an unconventional aspect when working outside ... [more ▼]

This report focuses on the classical Taylorian optimization of the cuting speed. An interesting result is the supply curve of the turning operation, which has an unconventional aspect when working outside of the productivity range [less ▲]

Local discretization errors are commonly done by inspecting local equilibrium errors. The difficulty lies in the fact that there is not, in general, a local convergence of equilibrium. Our point of view ... [more ▼]

Local discretization errors are commonly done by inspecting local equilibrium errors. The difficulty lies in the fact that there is not, in general, a local convergence of equilibrium. Our point of view is that desequilibrium has to be considered in its natural frame, which is the dual space. In other word, desequilibrium has to be measured by the work that it is able to produce. Such quasi-local error measures are presented. [less ▲]

Accelerated wear tests of tools are used from the pioneering works of brandsma in 1936. But their justification is often somewhat intuitive. A formalized description of these test is presented, based upon ... [more ▼]

Accelerated wear tests of tools are used from the pioneering works of brandsma in 1936. But their justification is often somewhat intuitive. A formalized description of these test is presented, based upon an analysis of the conditions of validity of the cumulative damage principle. This gives the basis for a comparison between proposed procedures. It is found that some of them make use of stronger hypotheses and are thus of less theoretical value. [less ▲]

Part 1 : The finite element formulation for fluid-structure problems - To the best of our knowledge, the first purely lagrangian formulation was proposed by Debongnie. At this time, even though natural ... [more ▼]

Part 1 : The finite element formulation for fluid-structure problems - To the best of our knowledge, the first purely lagrangian formulation was proposed by Debongnie. At this time, even though natural, this idea as well as the notion of displacement potential led to some surprises. Thes rationalizing efforts led to the final formulation of the corrected Tong's formulation in 1978 and to the corresponding formulation for the compressible case in 1984. Similar results were obtained by Morand in 1987. Here, contrarily to our preceeding papers, we present the formulation from a local point of view instead of a variational one. PART 2 : On the representation of rigid body modes with the SAMCEF formulation for hydroelastic problems - The question to see wether the SAMCEF formulation of hydroelastic problems respects the rigid body modes is often raised. It appear very often that some of the rotational rigid body modes are lost for the fre-free problem. The present report tries to give a better understanding of this problem. PART 3 - Dynamic analysis of fluid-structure problems : results. [less ▲]

The classical rolling bearing theory lies on the assumption that the rotational speed is low. The simplest correction for high speeds consists in adding only the centrifugal load. But even in this frame ... [more ▼]

The classical rolling bearing theory lies on the assumption that the rotational speed is low. The simplest correction for high speeds consists in adding only the centrifugal load. But even in this frame, the problem is by far complicated. However, in the case of a radial load, it is possible to develop an approximated formulation which easily leads to realistic results. This elementary theory may be used as a basis of comparison for more evolved theories, which may be useful. [less ▲]

The linearized study of pre-stressed structures is, by far, not a novelty. But its practical application led to a lot of disappointments, especially concerning rigid body modes, so that it seemed useful ... [more ▼]

The linearized study of pre-stressed structures is, by far, not a novelty. But its practical application led to a lot of disappointments, especially concerning rigid body modes, so that it seemed useful to try a restatement of this subject. After an exposition of the principles of this formulation, the attention is focused on the numerous simplifications which are commonly done, by tradition or for sake of simplicity. This study is illustrated by a lot of examples whose purpose is an aid for the physical understanding of the problem. [less ▲]

A frequently asked question is to know if the SAMCEF formulation of hydro-elastic problems allows a correct representation of the rigid body modes. In fact, it is current to analyse the free-free ... [more ▼]

A frequently asked question is to know if the SAMCEF formulation of hydro-elastic problems allows a correct representation of the rigid body modes. In fact, it is current to analyse the free-free vibrational problem, and some people were surprised to loose rotational rigid body modes. The purpose of the present report is to enlighten this point. [less ▲]

This paper analyses the U.T.C. formulation of hydroelastic problems, where the fluid is represented by an integral formulation. The common features of this formulation with the SAMCEF formulation are ... [more ▼]

This paper analyses the U.T.C. formulation of hydroelastic problems, where the fluid is represented by an integral formulation. The common features of this formulation with the SAMCEF formulation are enlighted and the difficult problem of the fluid-structure connexion is treated in detail. [less ▲]

This paper develops, from the technical linear contact concept, a step leading to an analytical prediction of the mutual displacement of two bodies in linear hertzian contact. The results are compared to ... [more ▼]

This paper develops, from the technical linear contact concept, a step leading to an analytical prediction of the mutual displacement of two bodies in linear hertzian contact. The results are compared to the approximate expressions of Dowson and Higginson, Lundberg, and Eschmann et al. [less ▲]

This report presents a program for the complete design of a deep groove ball bearing which is submitted to a plane sollicitation. This programs includes a catalogue consultation and the assessment of the ... [more ▼]

This report presents a program for the complete design of a deep groove ball bearing which is submitted to a plane sollicitation. This programs includes a catalogue consultation and the assessment of the tolerances of both races. For these, the computation is based on the exact nonlinear formulation of the problem, and not on approximate values of the catalogues. In particular, it allows to find the infuence of the clearance on the stiffness of the bearing. The bending moment is taken in account. In order to solve the nonlinear equations of the theory, a Newton-Raphson procedure is introduced. In this problem, a proper choice of the starting point is of paramount importance, as the reference position is stiffness-free. This problem is dicussed in detail. The second part of this report presents the ROULBI program and comments its different steps. [less ▲]